The iter* methods appear in Python 3, just without the iter prefix. Therefore it is good to use them in Python 2 because that makes it possible to translate the

The iter* methods appear in Python 3, just without the iter prefix. Therefore it is good to use them in Python 2 because that makes it possible to translate the code automatically with the 2to3 script. Otherwise possibly superfluous list conversion might get added, e.g., list(d.keys()).